In human anatomy, the fibularis brevis (or peroneus brevis) is a muscle that lies underneath the

fibularis longus In human anatomy, the fibularis longus (also known as peroneus longus) is a superficial muscle in the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body ( eversion) and to extend the foot downwa ...

within the

lateral compartment of the leg The lateral compartment of the leg is a fascial compartment of the lower leg. It contains muscles which make eversion and plantarflexion of the foot. Muscles The lateral compartment of the leg contains: * Fibularis longus * Fibularis brevis ...

. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to extend the foot downward away from the body at the

ankle The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joi ...

(plantar flexion).

Structure

1123 Muscles of the Leg that Move the Foot and Toes c

The fibularis brevis arises from the lower two-thirds of the lateral, or outward, surface of the

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity i ...

(inward in relation to the fibularis longus) and from the

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

between it and the muscles on the front and back of the leg. The muscle passes downward and ends in a tendon that runs behind the lateral malleolus of the ankle in a groove that it shares with the tendon of the fibularis longus; the groove is converted into a canal by the superior fibular retinaculum, and the tendons in it are contained in a common mucous sheath. The tendon then runs forward along the lateral side of the calcaneus, above the

calcaneal tubercle In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. ...

and the tendon of the fibularis longus. It inserts into the tuberosity at the base of the

fifth metatarsal The fifth metatarsal bone is a long bone in the foot, and is palpable along the distal outer edges of the feet. It is the second smallest of the five metatarsal bones. The fifth metatarsal is analogous to the fifth metacarpal bone in the hand. As ...

on its lateral side. The fibularis brevis is supplied by the superficial fibular (peroneal) nerve.

Function

The fibularis brevis is the strongest abductor of the foot. Together with the fibularis longus and the

tibialis posterior The tibialis posterior muscle is the most central of all the leg muscles, and is located in the deep posterior compartment of the leg. It is the key stabilizing muscle of the lower leg. Structure The tibialis posterior muscle originates on the ...

, it extends the foot downward away from the body at the ankle (plantar flexion). It opposes the

tibialis anterior The tibialis anterior muscle is a muscle in humans that originates along the upper two-thirds of the lateral (outside) surface of the tibia and inserts into the medial cuneiform and first metatarsal bones of the foot. It acts to dorsiflex and inve ...

and the

fibularis tertius In human anatomy, the fibularis tertius (also known as the peroneus tertius) is a muscle in the anterior compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body ( eversion) and to pull the foot upward toward ...

, which pull the foot upward toward the body (

dorsiflexion Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...

).'' Gray's Anatomy (1918), see infobox'' The fibularis longus also tilts the sole of the foot away from the midline of the body ( eversion). Together, the fibularis muscles help to steady the leg upon the foot, especially in standing on one leg.

Clinical significance

When the base of the fifth metatarsal is fractured, the fibularis brevis may pull on and displace the upper fragment (known as a

Jones fracture A Jones fracture is a broken bone in a specific part of the fifth metatarsal of the foot between the base and middle part that is known for its high rate of delayed healing or nonunion. It results in pain near the midportion of the foot on the ...

). An inversion sprain of the foot may pull the tendon such that it avulses the tuberosity at the base of the fifth metatarsal.

Nomenclature and etymology

Terminologia Anatomica ''Terminologia Anatomica'' is the international standard for human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology, a program of the International Federation of Associations of Anatomi ...

'' designates "fibularis" as the preferred word over "peroneus.". The word "peroneus" comes from the Greek word "perone," meaning pin of a brooch or a buckle. In medical terminology, the word refers to being of or relating to the fibula or to the outer portion of the leg.

Additional images

File:Gray357.png, Coronal section through right

and

subtalar joint In human anatomy, the subtalar joint, also known as the talocalcaneal joint, is a joint of the foot. It occurs at the meeting point of the talus and the calcaneus. The joint is classed structurally as a synovial joint, and functionally as a pla ...

s. (Label for Peroneus brevis is at right, third from the bottom.) Image:Gray258.png, Bones of the right leg, anterior surface. Image:Gray268.png, Bones of the right foot, dorsal surface. Image:Gray437.png, Muscles of the front of the leg. Image:Gray440 color.png, Cross-section through middle of leg. Image:Gray551.png, The popliteal, posterior tibial, and fibular arteries. Image:Gray1239.png, Back of left lower extremity. File:Slide16wwww.JPG, Fibularis brevis muscle File:Slide1ABBBA.JPG, Muscles of the sole of the foot. File:Slide1Bebe.JPG, Dorsum of Foot, deep dissection. File:Slide2xzxz.JPG, Muscles of leg, lateral view, deep dissection.

References

External links

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PTCentral
{{Authority control Muscles of the lower limb